A switch matrix provides switching between one or a plurality of input terminals and one or a plurality of output terminals. For microwave systems in particular, in order to provide the interconnectivity between multiple signal sources and loads, a switch matrix is required. For example, a high-speed switch matrix is used on space craft to provide interconnectivity among the multiple beam antennas. Key performance parameters for the switch matrix is insertion loss for the one connected path, isolation between inputs to the outputs for the nonconnected path(s) and switching speed of the switching elements from on-state to off-state.
Conventionally, PIN diodes or FETs have been used as the switching element in microwave integrated circuit (MIC) construction. The conventional elements in 50 ohm input and output circuits load down the transmission line in hybrid form and makes it narrow band for the switch matrix. With the advancement of monolithic microwave integrated circuits (MMICs), a new system architecture is desirable for the microwave switch matrix which has superior performance to conventional switch elements and is more simple in construction.